Species Interactions & Community Ecology

Competition
When multiple organisms seek the same limited resource
Resource Partitioning
A species will divide the resources they use in common by specializing in different ways
Example of Resource Partioning
One bird species might become more active in the morning and another species at night thus minimizing interference
Predation
The process by which individuals of one species hunt, capture, kill and consume individuals of another species
Parasitsm
A relationship in which one organism depends on the other for nourishment or some other benefit while simultaneously doing the host harm
Herbivory
When animals feed on the tissues of plants
Mutualism
A relationship in which two or more species benefit from interacting with one another
Symbiosis
Physically close association interacting species (whether parasitic or mutualistic)
Pollination
Insects, birds, bats and other creatures transfer pollen (containing male sex cells) from flower to flower, fertilizing ovaries (female sex cells) that grow into fruit with seeds
Trophic Level
Rank in the feeding hierarchy
Producers
Organisms that use the suns radiation directly to produce their own food comprise the first trophic level
Consumers
Organisms that consume producers are known as primary consumers and comprise the second trophic level
Detritivores & decomposers
Consume nonliving organic matter and play an essential role role as the community’s recyclers , making nutrients from organic matter available for reuse by living members of the community
Biomass
The collective mass of living matter in a given place and time
Food Web
A visual map of feeding relationships and energy flow that uses arrows to show the many paths by which energy passes among organisms as they consume one another
Keystone Species
A species that has a strong or wide-reaching impact far out of proportion to its abundance
Biome
A major regional complex of similar communitites
Invasive Species
Can alter a community substantially and are one of the central ecological forces in today’s world
Phase or Regime Shift
The overall character of the community fundamentally changes
Primary Succession
Follows a disturbance so severe that no vegetation or soil life remains from the community that occupied the site
Secondary Succession
When a disturbance dramatically alters an existing community but does not destroy all life or all organic matter in the soil